JPH1182802A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow no occurrence of coil disconnection resulting from corrosion, allow no corrosion of a magnetic member sticking face, and allow no occurrence of operation failure resulting from the biting of the dust into an attraction face or a sliding portion even if corrosive fluid or fluid containing dust is used. SOLUTION: A moving yoke is attracted to a fixed yoke by applying magnetomotive force by coils 7, 8, 9 to a magnetic circuit comprising fixed yokes 1, 2, 3, 5 and moving yokes 4, 6, and the moving yokes are parted from the fixed yokes by the elastic force of a spring 16 so as to open and close a fluid passage by a valve element 13 coupled to the moving yokes in a solenoid valve. A sticking face between the fixed yoke 5 communicate with the moving yoke 6 and a space containing the coils 7, 8, and a through hole 14a with the coupled body 15 of the moving yoke and the valve element 13 passing therethrough is sealed by a flexible seal member 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve suitable for shutting off a fluid containing corrosive fluid or dust.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a conventional on-off solenoid valve for opening and closing a fuel gas flow path. In the figure, the upper part from the center line shows the valve closed state, and the lower part from the center line shows the valve open state. The center shaft 1 shown in FIG. 8 is made of a magnetic member, and a first fixed magnetic member 2 and a second fixed magnetic member 3 are press-fitted at both ends thereof. . The first fixed magnetic member 2 has a substantially disk shape with a part cut away, and has an inclined end surface 2a. The second fixed magnetic member 3 has a bottomed cylindrical shape that is partially cut away. A first coil 7 is wound around the center shaft 1 via a coil bobbin 11.

[0003] A magnetic circuit case 9 made of aluminum die-casting is fastened to the central shaft 1 by screws 10, and the magnetic circuit case 9, the central shaft 1, the first fixed magnetic member 2 and the second fixed magnetic member 3 are fixed to each other. It is one. The movable magnetic member 4 is guided by a magnetic circuit case 9 and is slidably supported in the left-right direction in the figure. The current flowing through the first coil 7 gives a magnetomotive force to a magnetic circuit composed of the central shaft 1, the first fixed magnetic member 2, the movable magnetic member 4 and the second fixed magnetic member 3.

A third fixed magnetic member 5 having a partially cut-out U-shaped ring shape is fixed to the central shaft member 1 and the second fixed magnetic member 3, and the second coil is inserted into the U-shaped groove. 8 are arranged. The connecting member 15 has the movable magnetic member 4 and the magnetic contact piece 6 locked on one side, and the rubber valve 13 is held on the other side. The armature piece 6 faces the third fixed magnetic member 5 and forms a magnetic circuit with the fixed magnetic member 5. A magnetomotive force is given to the magnetic circuit by a current flowing through the second coil 8. A spacer 2 made of a resilient nonmagnetic material is provided between the armature 6 and the movable magnetic member 4.
The armature 6 is tiltable with respect to the movable magnetic member 4 within a predetermined angle range.

The valve case 12 having the valve seat 12a is fastened to the magnetic circuit case 9 and has a cylindrical cover 14 having a bottom.
Holding. The cover 14 is provided with an insertion opening 14a through which the connecting member 15 is inserted. A compression coil spring 16 is disposed between the cover 14 and the valve case 13 a covering the valve 13, and the valve 13, the connecting member 15, the movable magnetic member 4 and the armature 6 are illustrated by the compression coil spring 16. It is biased to the right.

The electrode 18 connected to the first coil 7 and the electrode 18 connected to the second coil 8 by a lead wire 19
A total of three electrodes 18 are fixed to the coil bobbin 11, that is, the electrodes 18 connected to the first coil 7 and the second coil 8, but two electrodes 18, 18 are shown in the figure. The cut surface in FIG. 8 is broken at the center line so as to pass through the two electrodes 18. Electrodes 18, 1 of magnetic circuit case 9
8 are sealed by O-rings 22, 22 ..., the hole through which the central shaft 1 is inserted is sealed by an O-ring 23, and the inside of the magnetic circuit case 9 is sealed from the atmosphere. .

In the above configuration, when the first coil 7 and the second coil 8 are not energized, no magnetomotive force acts on the respective magnetic circuits, and the valve body 13 is pressed against the valve seat 12a by the compression coil spring 16. The gas flow path indicated by the arrow of the valve case 12 is closed. When the first coil 7 and the second coil 8 are energized, the central shaft 1, the first fixed magnetic member 2, the movable magnetic member 4, and the second fixed magnetic member 3
Circuit consisting of: armature piece 6 and fixed magnetic member 5
Magnetomotive force acts on the magnetic circuit composed of the first and second magnetic members, so that these magnetomotive forces narrow the magnetic gap between the inclined end surface 2a of the first fixed magnetic member 2 and the inclined end surface 4a of the movable magnetic member 4. And the armature 6 is connected to the third fixed magnetic member 5.
Acts to approach.

As a result, the valve element 13 moves to the left in the figure, the contact piece 6 comes into close contact with the third fixed magnetic member 5, and the inclined end face 4a approaches the inclined end face 2a. Since the armature piece 6 is tiltable, it comes into close contact with the entire end surface of the fixed magnetic member 5. In this way, the valve is opened, but even if the energization of the first coil 7 is stopped thereafter, the valve is kept open while the second coil 8 is energized. Since the number of turns of the second coil 8 is large and the armature piece 6 and the fixed magnetic member 5 are in close contact with each other, the valve can be kept open only by passing a small current through the second coil 8.

When the power supply to the second coil 8 is stopped from this state, the valve body 13 is moved rightward by the elastic force of the compression coil spring 16 to be in a valve closed state. The armature 6 and the fixed magnetic member 5 are made of a member having a small residual magnetism.
Even if the fixed magnetic member 5 is in close contact with the compression coil spring 16
It is possible to move the valve body 13 with the elasticity of.

[0010]

In the above-described conventional on-off solenoid valve, the gas in the valve case 12 shown in FIG. 8 passes through the insertion opening 14a of the cover 14 as shown by an arrow, and the cover 14 and the valve case are connected to each other. After passing through the gap 12 and the gap between the magnetic circuit case 9 and the movable magnetic member 4, it enters the accommodating portions of the armature 6, the fixed magnetic member 5, the first coil 7 and the second coil 8. If this gas is corrosive, it may corrode the coil windings and break the coil.

If the gas is corrosive, the contact surface between the armature piece 6 and the fixed magnetic member 5 is corroded to weaken the attraction force between the armature piece 6 and the fixed magnetic member 5 to maintain the valve open state. There was a risk of disappearing.

When the gas contains dust, the dust enters the contact surface between the contact piece 6 and the fixed magnetic member 5 and weakens the attraction force between the contact piece 6 and the fixed magnetic member 5 to keep the valve open. There was a risk of disappearing. Further, when dust enters the sliding surface of the movable magnetic member 4, the movement of the movable magnetic member 4 may be hindered and the operation may be disabled.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electromagnetic valve which does not cause the above-mentioned problems even when used for a corrosive fluid or a fluid containing dust. It is.

[0014]

According to the solenoid valve of the present invention, a magnetomotive force generated by a coil is applied to a magnetic circuit formed by a fixed yoke and a movable yoke to cause the fixed yoke to attract the movable yoke. In the solenoid valve which separates the movable yoke from the fixed yoke and opens and closes the fluid flow path by a valve body connected to the movable yoke, the space for accommodating the adsorption surface of the fixed yoke and the movable yoke and the coil and the fluid flow path are formed. The insertion opening through which the connecting body between the movable yoke and the valve element is inserted is sealed with a flexible seal member.

Further, in the above-mentioned electromagnetic valve, a gap at a stationary portion between a suction surface of the fixed yoke and the movable yoke and a space accommodating the coil and the fluid flow path is sealed by a seal member.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solenoid valve according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an on-off solenoid valve according to a first embodiment of the present invention. Members having the same functions as the members of the conventional on-off solenoid valve described in FIG. 8 among the members of the on-off solenoid valve shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the context of the claims,
A fixed yoke is constituted by the central shaft body 1, the first fixed magnetic member 2, and the second fixed magnetic member 3, and a movable yoke cooperating therewith is constituted by the movable magnetic member 4. Further, a fixed yoke is constituted by the third fixed magnetic member 5, and a movable yoke cooperating therewith is constituted by the armature piece 6.

In the opening / closing solenoid valve 25 of the embodiment, a rubber boot 17 is mounted between the cover 14 and the connecting member 15. That is, the flange-shaped portion at one end of the boot 17 is sandwiched between the cover 14 and the boot retainer 20 and is pressed by the elastic force of the compression coil spring 16. The thick portion at the other end of the boot 17 is pushed into the groove of the connecting member 15. Thus, the boot 17 seals the space between the cover 14 and the connecting member 15.

The O-ring 21 is arranged at a position for sealing a gap between the cover 14 and the magnetic circuit case 9.
Other configurations are the same as those of the conventional on-off solenoid valve described with reference to FIG. 8, and operate similarly to open and close the gas flow path in the valve case 12.

However, the flow of gas in the valve case 12 is shut off at the positions indicated by the crosses in the figure. That is, the boot 17 and the O-ring 21 prevent gas from entering the space partitioned by the cover 14 and the magnetic circuit case 9.
Further, the O-ring 21 prevents gas from flowing through a gap between the cover 14 and the magnetic circuit case 9. Even if the gas is corrosive, the coil winding is not corroded and disconnected, and the contact surface between the armature piece 6 and the fixed magnetic member 5 is not corroded. Also, dust does not enter the contact surface between the armature piece 6 and the fixed magnetic member 5. As described above, the problem that has occurred in the conventional on-off solenoid valve has been improved.

FIG. 2 shows a water heater using the on-off solenoid valve 25 shown in FIG. The open / close solenoid valve 25 is arranged in the fuel gas supply path of the burner 52 and controls the supply of the fuel gas to the burner 52. The flow path of the water supplied to the water heater is opened and closed by a water valve 50. A water governor 51 is disposed in a flow path between the water valve 50 and the heat exchanger 53, and a water pressure responsive valve 51 a operated by the water governor 51 is used to supply a fuel gas flow between the on-off solenoid valve 25 and the burner 52. Located on the road.

When the water valve 50 is closed or the water supply is cut off, the water pressure of the water governor 51 drops, the water governor 51 closes the water pressure responsive valve 51a, and the supply of fuel gas to the burner 52 is stopped, so that the empty boiler is started. Is prevented. As described above, in the water heater using the on-off solenoid valve 25 of the present invention, even if a gas containing corrosive gas or dust is used as a fuel, the trouble caused by the on-off solenoid valve 25 does not occur for a long time.

FIG. 3 shows an on-off solenoid valve according to a second embodiment of the present invention. In this example, a diaphragm 30 is used instead of the boot 17 of the open / close solenoid valve according to the first embodiment described with reference to FIG.
Is used. The outer peripheral portion of the diaphragm 30 is pressed against the cover 14 by the compression coil spring 16, and the inner peripheral portion is fitted to the connecting member 15. Other configurations are the same as those of the opening / closing solenoid valve of the first embodiment. The illustration of the valve case 12 shown in FIG. 1 is omitted. As described above, the present invention can be implemented by using a diaphragm instead of the boot.

FIG. 4 shows an on-off solenoid valve according to a third embodiment of the present invention. In this example, a bellofram 32 is used instead of the boot 17 of the on-off solenoid valve according to the first embodiment described with reference to FIG. The outer periphery of the bellofram 32 is covered with a cover 14.
, And the inner peripheral portion is fitted to the connecting member 15. Other configurations are the same as those of the opening / closing solenoid valve of the first embodiment. The illustration of the valve case 12 shown in FIG. 1 is omitted. As described above, the present invention can be implemented by using a bellofram instead of the boot.

FIG. 5 shows an on-off solenoid valve according to a fourth embodiment of the present invention. In this example, a fixed yoke is formed by the case-shaped magnetic member 37, the center pole 36 fixed to the case-shaped magnetic member 37, and the lid-shaped magnetic member 38. A sleeve 60 is fitted between the center pole 36 and the lid-shaped magnetic member 38, and the plunger 34 is arranged so as to be guided and slid by the sleeve 60. The plunger 34 forms a movable yoke. A coil 39 for giving a magnetomotive force to a magnetic circuit composed of such a fixed yoke and a movable yoke is wound around the sleeve 60.

The plunger 34 has the valve body 13 fitted therein. The plunger 34 and the valve body 13 have the compression coil spring 1 attached thereto.
6 is urged upward in the figure. Although the illustration of the valve case 12 shown in FIG. 1 is omitted, the valve seat is closed by the upward movement of the valve body 13. The insertion opening of the plunger 34 is sealed with the boot 17.

When the coil 39 is energized, the magnetic flux acts to narrow the magnetic gap between the plunger 34 and the center pole 36, and the plunger 34 moves down to open the valve. When the energization of the coil 39 is stopped, the magnetic flux disappears and the plunger 34 moves upward by the elastic force of the compression coil spring 16 to close the valve. Boots 17 are plunger 34 and center pole 36
The gas is prevented from flowing into the suction surface of the coil 39 and the accommodating portion of the coil 39. As described above, the present invention can be applied to the plunger type solenoid valve.

FIG. 6 shows a safety device 42 according to a fifth embodiment of the present invention. This safety device is an extinguishing safety device that stops gas supply when the burner fire goes out.
9 is supplied with current by a thermocouple arranged in the flame of the pilot flame. The coil 39 is wound around the U-shaped magnetic member 39 to increase the number of turns so that a sufficient magnetomotive force can be obtained with a weak current. A suction piece 41 is slidably disposed at a position facing the U-shaped magnetic member 39. U-shaped magnetic member 39
Constitute a fixed yoke. Also, the suction piece 41
Constitutes a movable yoke.

The suction piece 41 is connected to the valve body 13 by the connecting member 15.
The valve body 13 is urged upward by a compression coil spring 16 in the figure. Although the illustration of the valve case is omitted, the valve seat is closed by the upward movement of the valve element 13. The insertion opening of the connecting member 15 is sealed with a boot 17. FIG. 7 shows details of a mounting portion of the boot 17.
Members having the same functions as those described with reference to FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

When a predetermined amount of electromotive force is generated in the thermocouple by the ignition of the spark, a predetermined amount of current flows through the coil 39. In this state, the U-shaped magnetic member 3 is
When the valve 13 is moved to the valve opening position where the suction piece 9 and the suction piece 41 are in contact with each other, the valve opening state is maintained by the magnetic flux between the U-shaped magnetic member 39 and the suction piece 41. When the ignition is extinguished for some reason, the degaussing is performed between the U-shaped magnetic member 39 and the adsorption piece 41, and the valve body 13 is moved to the valve closing position by the compression coil spring 16 to stop the outflow of the fuel gas.

The boot 17 prevents gas from flowing into the suction surface between the U-shaped magnetic member 39 and the suction piece 41 and the accommodating portion of the coil 39. As described above, the present invention can be applied to the safety device that disappears.

Although the embodiment has been described with respect to the case where the solenoid valve of the present invention is applied to opening and closing of the fuel gas passage, the invention can be applied to an electromagnetic valve which opens and closes the liquid passage.

[0032]

According to the solenoid valve of the present invention, even if it is used for a corrosive fluid or a fluid containing dust, the coil does not break due to corrosion, and the contact surface of the magnetic member does not corrode. Further, no malfunction occurs due to dust being caught in the suction surface or the sliding portion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an on-off solenoid valve according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a water heater using the opening / closing solenoid valve.

FIG. 3 is a sectional view showing an on-off solenoid valve according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing an on-off solenoid valve according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing an on-off solenoid valve according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing a safety device according to a fifth embodiment of the present invention. .

FIG. 7 is an enlarged sectional view showing a part of the safety device.

FIG. 8 is a sectional view showing an example of a conventional on-off solenoid valve.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 center shaft 2 first fixed magnetic member, 2a inclined end face 3 second fixed magnetic member 4 movable magnetic member, 4a inclined end face 5 third fixed magnetic member 6 armature piece 7 first coil 8 second Coil 9 Magnetic circuit case 10 Screw 11 Coil bobbin 12 Valve case, 12a Valve seat 13 Valve body, 13a Valve body case 14 Cover, 14a Insertion opening 15 Connection member 16 Compression coil spring 17 Boot 18 Electrode 19 Lead wire 20 Boot holder 21, 22 , 23 O-ring 24 Spacer 25 Opening / closing solenoid valve 30 Diaphragm 32 Velofram 34 Plunger 36 Center pole 37 Case-shaped magnetic member 38 Lid-shaped magnetic member 39 Coil 40 U-shaped magnetic member 41 Suction piece 42 Safety device 50 Water valve 51 Water governor, 51a Water pressure responsive valve 52 Burner 53 Heat exchanger 60 Sleeve

Claims (2)

[Claims] 1. A magnetic circuit formed by a fixed yoke and a movable yoke, a magnetomotive force generated by a coil is applied to cause the fixed yoke to attract the movable yoke, and the movable yoke is separated from the fixed yoke by a spring force. An electromagnetic valve that separates and opens and closes a fluid flow path with a valve body connected to the movable yoke, wherein the fluid flow path communicates with a suction surface of the fixed yoke and the movable yoke and a space accommodating the coil. An electromagnetic valve, wherein an insertion port through which a connecting body between a yoke and the valve element is inserted is sealed with a flexible seal member. 2. A sealing member for sealing a gap between a stationary portion between the fluid passage and the suction surface of the fixed yoke and the movable yoke and the space accommodating the coil and the fluid flow path. Item 1. The solenoid valve according to Item 1.